Spec 27/24 and the Boulton Paul Bittern

[PMN1]

The Bittern was a twin engined night fighter designed to Specification 27/24 but was a failure mostly it seems down to lack of performance.

What speed etc did 27/24 call for and would there have been engine options other than the Armstrong Siddeley Lynx the aircraft used that could have helped?

What other contenders were there?

 

[PMN1]

Video on the Bittern

View: https://www.youtube.com/watch?v=8AHdiqO7KN8

 

[Justo Miranda]

During the interwar period the British Air ministry continued to refine their night interception tactics using upward firing guns.

The Specification F 4/24, calling for a multi-seat twin-engine night defense fighter armed with two 37-mm C.O.W. cannons, led to the Bristol Bagshot and the Westland Westbury heavy fighters.

These designs were based on the French concept multiplace de combat that had been so successful in 1918.

The Bristol Type 95 Bagshot prototype (J7767) was flown on July 15, 1927 showing serious structural problems and the project was abandoned.

Bristol Type 95 technical data



Wingspan: 70 ft. (21.34 m), length: 45 ft. (13.69 m), height: 9.5 ft. (2.89 m), wing area: 840 sq. ft. (78 sq. m.), max weight: 8,195 lb. (3,717 kg), max speed: 125 mph (201 km/h), power plant: two Bristol Jupiter VI, nine cylinder, radial, air cooled engines rated at 450 hp. each, armament: two 37-mm Coventry Ordnance Works cannons and two 0.303-in Lewis machine guns.



The Westbury prototype (J7765) was flown in September 1926 and a second prototype (J7766) with a modified nose was flown in May 1927.

The first firing trials with C.O.W. cannons resulted in wing structural damage caused by the blast and recoil.

The concept was abandoned in favor of the Specification F 27/24 for a single-seat, twin-engine night fighter capable of breaking up groups of heavy bombers.

Westland Westbury technical data

Wingspan: 69 ft. (21 m), length: 43.3 ft. (13.2 m), height: 13.7 ft. (4.19 m), wing area: 875 sq. ft. (81.3 sq. m.), max weight: 7,887 lb. (3,573 kg), max speed: 125 mph (201 km/h), power plant: two Bristol Jupiter VIII, nine cylinder, radial, air cooled engines rated at 480 hp. each, armament: two 37-mm Coventry Ordnance Works cannons and two 0.303-in Lewis machine guns.

The Boulton Paul P.31 Bittern was designed to meet the Specification F 27/24.

The first prototype (J7936) was flown in February 1927 showing excessive wing flexibility and lack of lateral control.

The second machine (J7937) had re-designed wings with additional struts and was armed with two Lewis machine guns carried in revolving barbettes mounted in the fuselage sides.

Trials were not satisfactory because the low performance of the two airplanes.

The project was abandoned in favor of the Specification F 29/27.

Boulton Paul P.31 (J7936) technical data

Wingspan: 41 ft. (12.5 m), length: 32.3 ft. (9.86 m), height: 8.5 ft. (2.59 m), max weight: 4,500 lb. (2,041 kg), max speed: 152 mph (245 km/h), power plant: two Armstrong Siddeley Lynx, seven cylinder, radial, air cooled engines rated at 230 hp. each, armament: two 0.303-in Lewis machine guns.

Paint scheme: overall Dark Green (FS 34079) with six positions Type B low visibility roundels.

To meet the Specification F29/27, calling for a single-engine bomber-destroyer armed with one C.O.W. cannon, Vickers Aviation Ltd. submitted the Type 161 and Westland Aircraft Works the C.O.W. Gun Fighter, based in the Westland Interceptor F20/27.

Two prototypes were built, with the 37-mm cannon mounted to fire upwards aiming by means of a periscopic sight and the breech casing in the starboard side of the cockpit.

The Westland machine (J9565) was flown in December 1930 and the Vickers (J9566) on January 21, 1931.

Both aircraft were tested extensively until 1934 at the Martlesham Heath test center, but the RAF lost interest in the C.O.W. formula in favor of the new single engine fighters with mechanically driven turrets developed by the Boulton Paul Company.

In the thirties, fighter aircraft became obsolete very quickly and none of these concepts reached the production stage.

The cause of all these failures was the RAF Air Staff's demand that night fighters should have a low landing speed and a low wing loading.

This type of wings was inefficient at high speeds and all the night fighter designs proposed in the different specifications proved too slow to intercept the new Hendon-class bombers that appeared in 1930.

In the absence of specialized night fighters, some day interceptors were required to operate by night, a situation that lasted until June 1940.



Westland C.O.W. Gun Fighter technical data

Wingspan: 40.8 ft. (12.45 m), length: 29.8 ft. (9.10 m), height: 10.6 ft. (3.23 m), wing area: 223 sq. ft. (20.7 sq. m.), max weight: 3,943 lb. (1,786 kg), max speed: 185 mph (298 km/h), service ceiling: 27,900 ft. (8,506 m), power plant: one Bristol Mercury IIIA, nine cylinder, radial, air cooled engine rated at 485 hp., armament: one37-mm Coventry Ordnance Works cannon fixed upward firing at 58 degrees.

Paint scheme: overall Silver (aluminum dope) with Dark Green (FS 34079) dorsal area and six positions Type A roundels.

Vickers Type 161 technical data

Wingspan: 32 ft. (9.75 m), length: 23.5 ft. (7.16 m), height: 12.3 ft. (3.76 m), wing area: 270 sq. ft. (25 sq. m.), max weight: 3,355 lb. (1,520 kg), max speed: 185 mph (298 km/h), service ceiling: 22,396 ft. (6,828 m), power plant: one Bristol Jupiter VIIF, nine cylinder, radial, air cooled engine rated at 530 hp., armament: one 37-mm Coventry Ordnance Works cannon fixed upward firing at 43 degrees.

Paint scheme: overall Silver (aluminum dope) with six positions Type A roundels.

 

[Archibald]

The Caudron R.4, heavily armed close escorts for the Breguet XIVs. Together in La division aérienne they broke the German offensives of 1918, starting with Michael. A brilliant success that was fully and entirely forgotten 20 years later.

 

[Justo Miranda]

The Caudron R.4, heavily armed close escorts for the Breguet XIVs. Together in La division aérienne they broke the German offensives of 1918, starting with Michael. A brilliant success that was fully and entirely forgotten 20 years later.

- In the Western Front the French used night fighters of the Caudron R. XI and Sopwith Strutter types.

In February 1917 the Germans began using some Halberstadt D.II biplanes from the Fl.Abt.12 as night fighters.

Between May and August 1918, the Jasta 24, Jasta 73 and Jasta 74 used as night fighters specialized versions of the models Albatros D.II, D.III and DVa and Fokker D. VII.

At least one D.Va of the Jasta 38 was equipped with two 08/15 “Spandau” machine guns pointing upwards and forwards.

Between February 1918 and July 1922 the French Aéronautique Militaire used the Caudron R.XI heavy escort fighters from the Escadrille C 46, in joint operations with the Breguet XIV night bombers of the 3ême regiment de bombardement.

In 1924 a night fighter unit was officially created using Breguet XIV B2 bombers converted into night fighters, fitted with flare launchers and Vérain landing lamps on the lower wings.

The two types of aircraft: CAP (Chasse, Reconnaissance d’Armée et Protection) and CAN (Chasse et Reconnaissance d’Armée de Nuit), were called combattants de nuit and were replaced in 1926 by the Breguet Br. XIX B2 night bombers from the 23ème escadrille du 12ème RAB-Reims.

In 1932, forty Br. XIX B2 bombers were converted into Br. XIX CN2 (Chasseur de Nuit- Biplace) night escort fighters armed with two nose mounted machine guns.

Between 1932 and 1934 these aircraft were used by the 22ème and 23ème Escadrilles de Chasse de Nuit from GB III/22-Chartres.

Caudron R. XI C.3 technical data

Wingspan: 58.8 ft. (17.92 m), length: 36.8 ft. (11.22 m), height: 9.84 ft. (3 m), wing area: 602.7 sq. ft. (54.25 sq. m.), max weight: 4,779 lb. (2,165 kg), max speed: 114 mph (183 km/h), service ceiling: 19,516 ft. (5,950 m.), range: 110 miles (177 km), power plant: two Hispano-Suiza 8Bda, eight cylinder, Vee, liquid cooled engines rated at 215 hp. each, armament: five 7.7-mm Lewis machine guns.

Paint scheme (1919): overall three shades of Brun Foncé (Dark Brown /Federal Standard Reference FS 30045), Terre de Sienne (Sienna FS 30219), Vert Foncé (Dark Green FS 30219) and four positions cocardes (French roundels).

Breguet XIV CN2 technical data

Wingspan: 47 ft. (14.36 m), length: 28.8 ft. (8.87 m), height: 10.8 ft. (3.3 m), wing area: 540 sq. ft. (50.2 sq. m.), max weight: 3,900 lb. (1,769 kg), max speed: 121 mph (195 km/h), service ceiling: 20,300 ft. (6,200 m), power plant: two Renault 12 Fcx, twelve cylinder, Vee, liquid cooled engines rated at 300 hp. each, armament: two nose mounted 7.7-mm Vickers 7.7-mm and two movable 7.7-mm Lewis machine guns.

Paint scheme (1919): overall three shades of Brun Foncé (Dark Brown FS 30045), Terre de Sienne (Sienna FS 30219), Vert Foncé (Dark Green FS 30219) and four positions cocardes.

Breguet XIX CN2 technical data

Wingspan: 48.6 ft. (14.83 m), length: 31,5 ft. (9.61 m), height: 12 ft. (3.69 m), wing area: 538 sq. ft. (48.42 sq. m.), max weight: 5,511 lb. (2,500 kg), max speed: 133 mph (214 km/h), service ceiling: 23,620 ft. (7,200 m), range 497 miles (800 km), power plant: one Lorraine-Dietrich 12 Hb, twelve cylinder, Vee, liquid cooled engine rated at 500 hp., armament: two nose mounted 7.7-mm Vickers 7.7-mm and two movable 7.7-mm Lewis machine guns.

Paint scheme: overall Vert-Kaki (Dark Green FS 34257), Couleur Aluminium (Natural Metal) engine cowling and four positions cocardes.

 

[hesham]

Hi,

I think that,may Fairey and Hawker involved in this contest ?.

 

[Justo Miranda]

Hi,

I think that,may Fairey and Hawker involved in this contest ?.

- The Hawker Woodcock was designed as a night fighter to meet the Specification F.25/22.

The prototype (J6987) was flown in March 1923 showing poor manoeuvrability and flutter problems.

The aircraft was redesigned as Woodcock II and entered service with the No.3 Squadron in May of 1925 and with the No. 17 Squadron in March 1926, operating without any night flying equipment.

Although the Woodcock II was a good night flyer, it was a bad night fighter because of an insufficient view for the pilot and the clear view forward and upward was essential for night fighters.

It was replaced by the Gloster Gamecock.



Hawker Woodcock II technical data

Wingspan: 32.5 ft. (9.91 m), length: 26.2 ft. (7.98 m), height: 9.9 ft. (3.02 m), wing area: 346 sq. ft. (32.1 sq. m.), max weight: 2,979 lb. (1,351 kg), max speed: 141 mph (227 km/h), service ceiling: 22,500 ft. (6,900 m), range: 280 miles (450 km), power plant: one Bristol Jupiter IV, nine cylinder, radial, air cooled engine rated at 380 hp., armament: two fuselage mounted 0.303-in Vickers machine guns.

Paint scheme: Silver dope with Dark Grey cowlings.

In 1928, eighteen Gloster Gamecock day fighters (J8405 to J8422) from Nos. 3 and 17 Squadrons based at Upavon, were modified as night fighters fitted with exhausts flame dampers and R/T devices.

Gloster Gamecock technical data

Wingspan: 29.5 ft. (9 m), length: 19.6 ft. (6 m), height: 9.7 ft. (2.95 m), wing area: 264 sq. ft. (24.5 sq. m.), max weight: 2,860 lb. (1,297 kg), max speed: 155 mph (249 km/h), service ceiling: 22,100 ft. (6,700 m), range: 365 miles (587 km), power plant: one Bristol Jupiter VI, nine cylinder, radial, air cooled engine rated at 425 hp., armament: two fuselage mounted 0.303-in Vickers machine guns.

 

[PMN1]

Interesting...the Woodcock and Gamecock dont seem to have that much of a speed advantage over the Bittern and speed was one of the reasons given for the Bittern not proceeding.